– Microsoft said Friday that it is abandoning the “Aero” user interface with Windows 8, calling the UI that debuted in Vista and continued in Windows 7, “cheesy” and “dated.”

In a massive 11,300-word blog post, Jensen Harris, the director of program management for Windows 8’s user experience team, said that the new operating system’s look-and-feel, its graphics user interface, or GUI, would be “clean and crisp,” and would do away with the “glass and reflections” that marked Aero.

The move was Microsoft’s attempt to bring the traditional desktop — one of two GUIs in Windows 8 — closer to the new Metro-style interface, said Harris.

“In the end, we decided to bring the desktop closer to the Metro aesthetic, while preserving the compatibility afforded by not changing the size of window chrome, controls, or system UI,” said Harris. “We have moved beyond Aero Glass — flattening surfaces, removing reflections, and scaling back distracting gradients.”

Aero first appeared in Windows Vista, which reached enterprises in late 2006 and consumers in early 2007, but Microsoft had been working on the GUI for years. The company showed elements of Aero in 2005 betas it distributed to select testers, for example.

Windows 7 also relied on Aero, although Microsoft tweaked the GUI, adding features like “Snap,” which automatically sized a window to half the screen, and changing the translucency of maximized windows.

Users will not get to see Windows 8’s new GUI until the operating system appears in final form later this year. “While a few of these visual changes are hinted at in the upcoming Release Preview, most of them will not yet be publicly available,” Harris acknowledged.

It’s unusual for Microsoft to keep a Windows GUI under wraps until final release: Both Vista and Windows 7 showed the finished Aero UI, or at the least, major chunks of it, months, even years, before those editions went on sale.

Other than derogatory references to Aero as first implemented in Vista — when Harris said, “This style of simulating faux-realistic materials (such as glass or aluminum) on the screen looks dated and cheesy now.” — he did not give explicit reasons for dropping Aero from the desktop, other than Microsoft’s desire to shift it closer to the new Metro design philosophy.

In a long section of his post, however, Harris called out seven goals of the Windows 8 GUI redesign. Most applied primarily to Metro, and secondly, to touch-based devices like tablets, or in a broader sense, to mobile devices where battery power is tight and longevity a critical concern.

Microsoft won’t unveil the full Windows 8 desktop UI until this fall, but this screenshot of the Windows Explorer file manager is a sample of what the final will look like. (Image: Microsoft.)